Study links CT scans to cancer risk

A large American study suggests that the radiation used in computed tomography (CT) scans could increase the long-term risk of certain cancers. Researchers from the University of California, San Francisco, found that CT scans might be responsible for 5% of all cancers each year, potentially leading to over 100,000 new cancer cases annually in the United States.

Radiation exposure and cancer risk

CT scans are widely used to detect tumors and diagnose diseases, but they expose patients to ionizing radiation, which has been linked to cancer in some studies. The research, funded by the National Institutes of Health, examined the relationship between radiation exposure and cancer risk based on CT scans performed in 2023.

Scope of the study

The study analyzed data from 93 million CT scans conducted on 61.5 million patients in the U.S. The number of scans increased with age, peaking among adults aged 60 to 69. Children accounted for 4.2% of the scans, and tests performed in the last year of a patient's life were excluded, as they were unlikely to lead to cancer.

Cancer risk by age and gender

Adults aged 50 to 59 were projected to have the highest number of cancer cases linked to CT scans, with 10,400 cases in women and 9,300 in men. The most common cancers identified were lung, colon, leukemia, bladder, and breast cancer.

Cancer risk in children

Among children, the study found that the most frequently suspected cancers linked to CT scans were brain and thyroid cancers. These findings highlight the need for careful consideration of the risks and benefits of CT scans in pediatric patients.